Process of rolling sheet metal.



- Patented May 28, I901.

G. DAVIES.

PROCESS OF ROLLING SHEET METAL.

(Application filed Aug. 20, 1900.)

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No. 674,855. Patented May 28, l90l.

- G'."DAVIES.

PROCESS OF ROLLING SHEET METAL.

(Application filed Aug. 20, mo.)

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llrTTTnn STATES PATENT OFFICE.

. GRIFFITH DAVIES, OF APOLLO, PENNSYLVANIA.

PROCESS OF ROLLING SHEET METAL.

SPECIFICATION forming part of Letters Patent No. 674,855, dated May 28, 1901.

Application filed August 20, 1900.

T aZZ whmm it may concern.-

Be it known that I, GRIFFITH DAVIES, a resident of Apollo, in the county of Armstrong and State of Pennsylvania, have invented a new and useful Improvement in Processes of Rolling Sheet Metal; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to a process of rolling sheet metal, and has for its object a method of rolling such metal which greatly reduces the cost of labor incident thereto, which obviates the necessity for the numerous reheatings, and which reduces the amount of waste resulting from trimming the edges of the packs, which is necessary in the present methods of rolling sheet metal.

The most common method of rolling sheet metal as at present practiced consists in heating the plate-bars to a suitable rolling temperature and then reducing them in suitable roughing-rolls to comparatively thin sheets, the bars being fed sidewise to the rolls. The general practice is to reduce two bars at a time, one following the other in quick succession through the rolls and the upper roll being screwed down after each pass until it is tight against the lower roll. The adj ustingscrews are then slacked a little and the two sheets previously reduced are placed one on top of the other and passed through the rolls, the temperature of the sheets being so reduced in the previous rolling operation as to prevent their welding together. As soon as all the bars forming one heat or charge of the sheet-bar furnace have been reduced to sheets in this manner three or four of such sheets are placed one on top of the other, heated in a special furnace, and then rolled as thin as possible in suitable rolls. The sheets are then separated, arranged in piles or packs of five or six, again charged into the furnace, heated, and again rolled, and after being thus reduced to the desired gage the edges of the pile or pack are trimmed, thus producing sheets of the required dimensions. It has also been proposed to reduce a slab or plate-bar to a sheet having a width approximately equal to that of the sheets to be formed and a length equal to several finished sheets and then fold this sheet over several times upon itself, thereby forming a pack, which is then heated and Serial No. 27,432. (No specimens.)

rolled until the layers in the pack are reduced to the desired gage. The edges of this pack are then trimmed off, producing sheets of the desired dimensions. posed to take a plate of about No. 16 gage in thickness, fifteen inches wide, and twenty feet long, heat it in a furnace of suitable length, and then pass it lengthwise between a pair of plating-rolls, the upper roll being screwed down tight upon the lower roll, after which it is folded over, forming a double strip of half the length. The folded strip is then drawn through a reheating furnace and passed between another set of rolls. The two layers are then opened up, and two or more such strips similarly treated are arranged in a pack consisting of four, six, or more layers and then charged into another heating-furnace, and after being properly reheated are again passed through suitable rolls. The pack is then again opened up, separating the several layers, after which the parts are again folded, charged into a reheating-furnace, and again rolled. These operations are continued until the layers forming the pack have been reduced to the desired gage, after which the ends and edges of the pack are trimmed off, forming sheets of the desired dimensions.

In each of the foregoing operations it. will be observed that a large number of reheatings are necessary, which, together with the manipulations necessary in folding or piling the sheets to form packs and opening up the same, require a large force of laborers, thereby greatly adding to the cost of production, while the nature of the manipulations limits the output of a mill. Furthermore, all the edges of every sheet on the pack are trimmed off, thereby causing a large amount of waste, and in rolling in packs the sheets are liable to stick or weld to each other, thereby causing a further loss. In none of the methods heretofore employed for rolling sheet metal has it been possible to do away with the folding or forming of the sheets into packs, for the reason that the slack in the adj usting-screws of the rolls is so great that the sheets cannot be reduced to the desired gage without piling a number of them one upon the other. This is true notwithstanding the fact that the screws of the rolls are set down as tight as possible.

It has also been pro It is the object of my invention to overcome these defects in the ordinary methods of rolling sheet metal; and to this end it consists in taking a plate-bar of the desired dimensions, heating it to a suitable rolling temperature in an ordinary heating-furnace, then passing it sidewise through suitable roughingrolls, as at present practiced, then at the same heat passing it between suitable hot rolls until it is reduced to approximately a No. 12 gage, after which the long strip is fed in succession through passes of two sets of plain-faced four-high rolls, the metal passing in a circuitous path between the meeting faces of each two adjacent rolls in each set, so that it receives three reductions in each set, the rolls of each set resting by gravity one upon the other and the adjusting-screws ,of the first set being set rather loosely, while the screws of the second set are set down tight.

In order to enable others to practice my invention, I will now describe the same more fully, referring to the accompanying drawings, in which- Figure 1 is a plan view of suitable apparatus for practicing my invention. Fig. 2 is a side elevation of the same. Fig. 3 is a longitudinal section of the two sets of four-high rolls. Fig. 4 is a front elevation of one of said sets of rolls, and Fig. 5 is a front elevation of the roughing and hot rolls.

In the drawings, 1 represents a suitable plate-bar-heating furnace, in front of which is located a stand of two-high roughing-rolls 2'.

3 represents a stand of three-high hot rolls, shown as coupled directly to the roughingrolls 2; but the same may be placed in any suitable position with reference thereto and driven in any desired manner.

4 and 5 indicate two similar stands of fourhigh rolls, each of said stands comprising housings 6, having vertical openings therein for receiving the journals of the rolls 7 8 9 10. Each of these rolls has its working face formed straight from end to end, and said working faces rest directly upon each other, no journal-boxes being interposed between the journals of the several rolls. The upper roll is provided with upper j ournal-boxes 11, against which impinge the lower ends of adjustingscrews 12. By this means the several rolls can be set down tightly upon each other. Suitable semicircular guides 13 are secured to the housings 6 for directing the sheet metal from one pass of said rolls back through the next higher pass, two such guides being employed in each stand of rolls. These rolls and guides are of a type familiarly known as repeating-mills, and no special features of construction are present therein. To the rear of the stand 5 are rotating shears 14 for trimming the edges of the sheets as they emerge from the last pass of the rolls. In some cases it may be found desirable to employ an auxiliary reheating-furnace, which is preferably located between the stands of rolls 4 and 5 and may be any ordinary form of reheatingfurnace 15, provided with openings 16 on its opposite side and above the fireplace thereof, through which openings the sheet passes in its course from the stand 4 to the stand 5.

In the practice of my invention the platebar of proper dimensions is heated to a good rolling temperature in the furnace 1, after which it is roughed down in the roughingrolls 2,the plate being passed sidewise through said rolls and being returned over the top roll to the front thereof, as is now commonly practiced. After being rolled to such a length that it is inconvenient to pass it back over the top of the rolls it is taken to the hot rolls 3 and passed through said rolls back and forth, going in one direction through one pass and in the opposite direction through the other pass until it is reduced to approximately a 12 gage and of considerable length. The end of the sheet is then led to the lower pass of the stand of rolls 4 and fed between the rolls 7 and 8, the guide 13 returning it through the pass between the rolls 8 and 9 and the other guide 13 returning it through the pass between the rolls 9 and'lO. The screws for this stand of rolls are set down loosely and the amount of slack between said rolls and screws is divided between the three passes, so that the sheet is reduced to the same extent that it would be reduced if it were folded into three layers and passed through a pair of ordinary rolls. The sheet is led to the lower pass of the stand of rolls 5, and if its temperature has fallen below a good rolling heat the auxiliary furnace 15 is used. It is passed through the various passes between the rolls of the stand 5 in precisely the same manner that it was passed through the rolls in the stand 4, but the adj usting-screws of the stand 5 are set down tight, and whatever slight amount of slack may exist'between said rolls and adjusting-screws is likewise divided into three parts, so that the sheet is again materially reduced in thickness. The three passes through the rolls 4 reduce the sheet to approximately 20 gage, while the three passes through the rolls 5 reduce it to approximately 27 gage, which is the ordinary gage of sheets used for tin-plate. If, however, it should be desired to reduce the same to a still thinner gage, the sheet would be folded once upon itself and again passed through the rolls 4 and 5. On emerging from the rolls 5 the edges of the sheet are trimmed off by the rotary shears 14, after which the sheet is cut into the desired length. It is essential that the working faces of the several rolls be perfectly straight. Hence the rolls should not be permitted to expand too much, owing to the heat of the sheets, and should therefore be occasionally flushed with water, but not to such an extent as to cool the sheet too rapidly.

It will be observed that by my method of rolling sheet metal the same is reduced to the desired gage at the original heat of the plate-bar, that no folding or packing of the same is necessary, and that the only waste that is formed is due to trimming ofi the side edges of the sheet. In case it should be found necessary to fold the sheet once upon itself very little waste would result-namely, that due to the single fold. It is found that my process of rolling sheet metal very materially reduces the cost of rolling, the laborers necessary to fold or form the packs, re heat and open up the same, and those necessary to direct the packs through the rolls to reduce the sheets from 12 gage to 27 gage being entirely dispensed with. Furthermore, the usual reheating-furnaces are dispensed with, the loss from the layers of the packs adhering to each other does not occur, the Waste due to trimming the ends of the packs is obviated, and the output is greatly increased, being equal to that of three hot mills.

What I claim, and desire to secure by Letters Patent, is

1. The method of rolling sheet metal, which consists in heating the plate-bar, reducing the same by rolling to approximately 12 gage and then at the same heat passing the sheet in a circuitous path through the several passes formed by a plurality of plain-faced rolls each resting one on the other and held against each other by unyielding means.

2. The method of rolling sheet metal which consists in heating a plate-bar, reducing the same by rolling to approximately 12 gage, then at the same heat passing the sheet in a circuitous path through the several passes formed by a plurality of plain-faced rolls each resting one on the other and held loosely against one another by yielding means and then while still at the same heat, passing the sheet in a similar manner through a similar set of rolls set tightly against each other.

In testimony whereof I, the said GRIFFITH DAVIES, have hereunto set my hand.

GRIFFITH DAVIES.

Witnesses:

F. W. WINTER, ROBERT C. TOTTEN. 

